Heat Waves Are a Growing Threat to Europe’s Nuclear Power Supply
(Bloomberg) -- Heat waves across Europe are increasing the need for nuclear power plants to be taken offline, with the situation expected to worsen in the coming decades and few options for mitigation.
Weather-related nuclear outages, mainly caused by elevated temperatures of cooling water, increased threefold in the period from 2010 to 2019, compared with 1990 to 2009, according to a study published in Energy Economics. Due to climate change, the intensity and length of these heat waves is expected to increase.
“Summer heat waves are climbing fast — 0.85 more days each year since 2010,” said Jess Hicks, a weather analyst at BloombergNEF. “That trajectory spells growing cooling-water risks for French nuclear plants.”
Europe is building out its renewable energy capacity, but sources of baseload power such as nuclear are still crucial for maintaining stable electricity flows when the sun isn’t shining or the wind isn’t blowing. That’s especially important on hot summer days, when power demand can surge as people switch on air conditioners.
See also: European Gas Prices Rise as EDF Warns of French Nuclear Cuts
A separate study published in the journal Energy in April looked at two reactors operated by Electricite de France SA, Chooz and Golfech, which rely on river water for cooling. It concluded that climate change will increase water temperature and also reduce flow volumes. If both plants are still operating by 2050, the level of outages would have doubled at Chooz and increased tenfold for Golfech. In the worst years, about 14% of Chooz’s generation would need to be curtailed.
When faced with high water temperatures and low flows, nuclear operators have limited options.
A closed-cycle cooling system, which relies less on the external environment, is one option. However, the Energy Economics study found that retrofitting such systems would cost about $500 million per nuclear power plant.
Another option would be to relax environmental limits on river temperatures, allowing reactors to keep operating for longer during heat waves. Such restrictions have been waived in the past, for example in 2022 when the French nuclear regulator ASN temporarily allowed five nuclear plants to discharge hotter water into rivers as the nation struggled with an energy crisis.
EDF has been studying other methods to reduce water consumption at nuclear power plants, such as capturing the cooling vapor given off by the facilities.
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